It is recalled that a zeolite is a material having pores of a diameter that is greater than the smallest dimension of a water molecule and having electric charge that attracts water molecules. These characteristics confer on zeolite the power to adsorb water in a manner that is advantageous in the field of dehydration.
Dehydration by means of zeolites, or “zeodration”, is generally performed by means of an installation having a first enclosure and a nearby second enclosure in communication therewith. The first enclosure is arranged to receive products for dehydrating and the second enclosure receives zeolites and is fitted with a pump for sucking out the air contained in the enclosures. The suction pump establishes low pressure in the enclosures that encourages the water contained in the products to evaporate, which products are possibly heated. The water vapor passes into the second enclosure where it is trapped in the zeolites. That type of dehydration is particularly effective.
Nevertheless, a fraction of the aromas are nevertheless extracted from the products. These aromas are to be found in the second enclosure prior to being evacuated by the pump. This spoils the organoleptic qualities of the dehydrated products.
Proposals have been made for an installation for dehydrating products, in particular food products, that is effective while nevertheless minimizing harm to the qualities of the products, and in particular the organoleptic properties for food products.
One such installation, described in document FR-A-2 868 520 comprises an enclosure, a member for sucking out the air contained in the enclosure, a product container that is received inside the enclosure and that is provided with a top opening, an air- and water-permeable bottom of a cassette extending in register therewith, the cassette containing moisture-adsorption means. The cassette overlies the container and cooperates therewith to define a compartment from which air is sucked out through the adsorption means, thereby keeping the aromas that escape during the evaporation of the water contained in the products in the neighborhood of those products.
The performance of those installations is quite remarkable and it might seem impossible to improve it.